Original Research ARTICLE
Molecular characterization of Mycobacterium avium subsp. hominissuis isolated from lymph nodes of Swiss cattle at slaughter
- 1Institut für Veterinärbakteriologie, Vetsuisse Fakultät, Universität Zürich, Switzerland
- 2Institut für Lebensmittelsicherheit und -hygiene, Universität Zürich, Switzerland
Mycobacterium avium subsp. hominissuis (MAH) is an important zoonotic pathogen with raising global health concerns. In humans, MAH is one of the most widespread non-tuberculous mycobacterial species responsible for lung disease. In animals, MAH is frequently isolated from pigs; however, it is also an opportunistic pathogen for other mammals including cattle. To elucidate the genetic diversity of MAH in cattle, a molecular characterization of isolates (n = 26) derived from lymph nodes was performed. Fourteen isolates originated from slaughtered cattle with visible altered lymph nodes at meat inspection whereas twelve isolates were from lymph nodes without any gross pathological changes of healthy slaughtered cattle.
Variable number of tandem repeat (VNTR) analysis was performed at 20 loci to examine genetic differences of isolates and to compare to previously reported VNTR data of human isolates from different countries. Genetic elements IS901, IS1245, IS1311, LSPA17, ITS1 sequevar and hsp65 code were determined. Interestingly, two bovine MAH isolates harbored ISMav6 and hsp65 code 15, which so far has only been observed in human isolates.
We supposed that VNTR data of Swiss samples would show clustering with European samples. Minimum spanning tree and unweighted pair group method using arithmetic averages analyses based on the VNTR data indicated a specific cluster of MAH isolates obtained from lymph nodes without any gross pathological changes of healthy slaughtered cattle. Comparing Swiss isolates with isolates from different other countries no geographical clustering was observed; however, four Swiss isolates had an identical VNTR profile as human isolates from the Netherlands, USA and Japan. These findings indicate a possible public health issue.
Keywords: M. avium subsp. hominissuis, VNTR, ISMav6, hsp65 code, ITS1 sequevar, Cattle, Lymph Nodes
Received: 07 Nov 2017;
Accepted: 15 Feb 2018.
Edited by:Subhash Verma, Chaudhary Sarwan Kumar Himachal Pradesh Krishi Vishvavidyalaya, India
Reviewed by:Kaori Sakamoto, University of Georgia, United States
Sunil K. Mor, University of Minnesota Twin Cities, United States
Copyright: © 2018 Scherrer, Landolt, Carroli and Stephan. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Ms. Simone Scherrer, Institut für Veterinärbakteriologie, Vetsuisse Fakultät, Universität Zürich, Winterthurerstrasse 270, Zurich, 8057, Switzerland, firstname.lastname@example.org